1. Field of the Invention
The present invention relates to a semiconductor device and a method of manufacturing a semiconductor device.
2. Description of the Related Art
An insulated gate bipolar transistor (IGBT) is one type of power semiconductor devices. The IGBT is a power semiconductor element having the high-speed switching characteristics and voltage driving characteristics of a metal oxide semiconductor field effect transistor (MOSFET), and the low on-voltage characteristics of a bipolar transistor. The IGBT has been expanding the application fields thereof from the industrial field (e.g., a general-purpose inverter, an AC servo, an uninterruptible power source (UPS), a switching power supply, etc.) to the home appliance field (e.g., an electronic oven, a rice cooker, a stroboscope, etc.).
A power conversion apparatus using semiconductor elements has been studied in which a bidirectional switching element is applied to a direct conversion circuit such as a matrix converter, in order to perform AC (alternating current)/AC conversion, thereby reducing the size, weight, and cost of a circuit and improving the efficiency and response speed of the circuit. The bidirectional switching element is formed by connecting an IGBT and an anti-parallel diode (hereinafter, referred to as reverse blocking IGBTs) having capability (hereinafter, referred to as reverse blocking capability) to a reverse voltage in parallel. Therefore, there is a demand for the development of the reverse blocking IGBT.